1 /*
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  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
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 24 
 25 #ifndef SHARE_GC_PARALLEL_PARALLELSCAVENGEHEAP_HPP
 26 #define SHARE_GC_PARALLEL_PARALLELSCAVENGEHEAP_HPP
 27 
 28 #include "gc/parallel/generationSizer.hpp"
 29 #include "gc/parallel/objectStartArray.hpp"
 30 #include "gc/parallel/psGCAdaptivePolicyCounters.hpp"
 31 #include "gc/parallel/psOldGen.hpp"
 32 #include "gc/parallel/psYoungGen.hpp"
 33 #include "gc/shared/cardTableBarrierSet.hpp"
 34 #include "gc/shared/collectedHeap.hpp"
 35 #include "gc/shared/collectorPolicy.hpp"
 36 #include "gc/shared/gcPolicyCounters.hpp"
 37 #include "gc/shared/gcWhen.hpp"
 38 #include "gc/shared/softRefPolicy.hpp"
 39 #include "gc/shared/strongRootsScope.hpp"
 40 #include "memory/metaspace.hpp"
 41 #include "utilities/growableArray.hpp"
 42 #include "utilities/ostream.hpp"
 43 
 44 class AdjoiningGenerations;
 45 class GCHeapSummary;
 46 class GCTaskManager;
 47 class MemoryManager;
 48 class MemoryPool;
 49 class PSAdaptiveSizePolicy;
 50 class PSCardTable;
 51 class PSHeapSummary;
 52 
 53 class ParallelScavengeHeap : public CollectedHeap {
 54   friend class VMStructs;
 55  private:
 56   static PSYoungGen* _young_gen;
 57   static PSOldGen*   _old_gen;
 58 
 59   // Sizing policy for entire heap
 60   static PSAdaptiveSizePolicy*       _size_policy;
 61   static PSGCAdaptivePolicyCounters* _gc_policy_counters;
 62 
 63   GenerationSizer* _collector_policy;
 64 
 65   SoftRefPolicy _soft_ref_policy;
 66 
 67   // Collection of generations that are adjacent in the
 68   // space reserved for the heap.
 69   AdjoiningGenerations* _gens;
 70   unsigned int _death_march_count;
 71 
 72   // The task manager
 73   static GCTaskManager* _gc_task_manager;
 74 
 75   GCMemoryManager* _young_manager;
 76   GCMemoryManager* _old_manager;
 77 
 78   MemoryPool* _eden_pool;
 79   MemoryPool* _survivor_pool;
 80   MemoryPool* _old_pool;
 81 
 82   virtual void initialize_serviceability();
 83 
 84   void trace_heap(GCWhen::Type when, const GCTracer* tracer);
 85 
 86  protected:
 87   static inline size_t total_invocations();
 88   HeapWord* allocate_new_tlab(size_t min_size, size_t requested_size, size_t* actual_size);
 89 
 90   inline bool should_alloc_in_eden(size_t size) const;
 91   inline void death_march_check(HeapWord* const result, size_t size);
 92   HeapWord* mem_allocate_old_gen(size_t size);
 93 
 94  public:
 95   ParallelScavengeHeap(GenerationSizer* policy) :
 96     CollectedHeap(),
 97     _collector_policy(policy),
 98     _gens(NULL),
 99     _death_march_count(0),
100     _young_manager(NULL),
101     _old_manager(NULL),
102     _eden_pool(NULL),
103     _survivor_pool(NULL),
104     _old_pool(NULL) { }
105 
106   // For use by VM operations
107   enum CollectionType {
108     Scavenge,
109     MarkSweep
110   };
111 
112   virtual Name kind() const {
113     return CollectedHeap::Parallel;
114   }
115 
116   virtual const char* name() const {
117     return "Parallel";
118   }
119 
120   virtual CollectorPolicy* collector_policy() const { return _collector_policy; }
121 
122   virtual GenerationSizer* ps_collector_policy() const { return _collector_policy; }
123 
124   virtual SoftRefPolicy* soft_ref_policy() { return &_soft_ref_policy; }
125 
126   virtual GrowableArray<GCMemoryManager*> memory_managers();
127   virtual GrowableArray<MemoryPool*> memory_pools();
128 
129   static PSYoungGen* young_gen() { return _young_gen; }
130   static PSOldGen* old_gen()     { return _old_gen; }
131 
132   virtual PSAdaptiveSizePolicy* size_policy() { return _size_policy; }
133 
134   static PSGCAdaptivePolicyCounters* gc_policy_counters() { return _gc_policy_counters; }
135 
136   static ParallelScavengeHeap* heap();
137 
138   static GCTaskManager* const gc_task_manager() { return _gc_task_manager; }
139 
140   CardTableBarrierSet* barrier_set();
141   PSCardTable* card_table();
142 
143   AdjoiningGenerations* gens() { return _gens; }
144 
145   // Returns JNI_OK on success
146   virtual jint initialize();
147 
148   void post_initialize();
149   void update_counters();
150 
151   // The alignment used for the various areas
152   size_t space_alignment()      { return _collector_policy->space_alignment(); }
153   size_t generation_alignment() { return _collector_policy->gen_alignment(); }
154 
155   // Return the (conservative) maximum heap alignment
156   static size_t conservative_max_heap_alignment() {
157     return CollectorPolicy::compute_heap_alignment();
158   }
159 
160   size_t capacity() const;
161   size_t used() const;
162 
163   // Return "true" if all generations have reached the
164   // maximal committed limit that they can reach, without a garbage
165   // collection.
166   virtual bool is_maximal_no_gc() const;
167 
168   virtual void register_nmethod(nmethod* nm);
169   virtual void unregister_nmethod(nmethod* nm);
170   virtual void verify_nmethod(nmethod* nm);
171   virtual void flush_nmethod(nmethod* nm);
172 
173   void prune_scavengable_nmethods();
174 
175   size_t max_capacity() const;
176 
177   // Whether p is in the allocated part of the heap
178   bool is_in(const void* p) const;
179 
180   bool is_in_reserved(const void* p) const;
181 
182   bool is_in_young(oop p);  // reserved part
183   bool is_in_old(oop p);    // reserved part
184 
185   // Memory allocation.   "gc_time_limit_was_exceeded" will
186   // be set to true if the adaptive size policy determine that
187   // an excessive amount of time is being spent doing collections
188   // and caused a NULL to be returned.  If a NULL is not returned,
189   // "gc_time_limit_was_exceeded" has an undefined meaning.
190   HeapWord* mem_allocate(size_t size, bool* gc_overhead_limit_was_exceeded);
191 
192   // Allocation attempt(s) during a safepoint. It should never be called
193   // to allocate a new TLAB as this allocation might be satisfied out
194   // of the old generation.
195   HeapWord* failed_mem_allocate(size_t size);
196 
197   // Support for System.gc()
198   void collect(GCCause::Cause cause);
199 
200   // These also should be called by the vm thread at a safepoint (e.g., from a
201   // VM operation).
202   //
203   // The first collects the young generation only, unless the scavenge fails; it
204   // will then attempt a full gc.  The second collects the entire heap; if
205   // maximum_compaction is true, it will compact everything and clear all soft
206   // references.
207   inline void invoke_scavenge();
208 
209   // Perform a full collection
210   virtual void do_full_collection(bool clear_all_soft_refs);
211 
212   bool supports_inline_contig_alloc() const { return !UseNUMA; }
213 
214   HeapWord* volatile* top_addr() const { return !UseNUMA ? young_gen()->top_addr() : (HeapWord* volatile*)-1; }
215   HeapWord** end_addr() const { return !UseNUMA ? young_gen()->end_addr() : (HeapWord**)-1; }
216 
217   void ensure_parsability(bool retire_tlabs);
218   void resize_all_tlabs();
219 
220   bool supports_tlab_allocation() const { return true; }
221 
222   size_t tlab_capacity(Thread* thr) const;
223   size_t tlab_used(Thread* thr) const;
224   size_t unsafe_max_tlab_alloc(Thread* thr) const;
225 
226   void object_iterate(ObjectClosure* cl);
227   void safe_object_iterate(ObjectClosure* cl) { object_iterate(cl); }
228 
229   HeapWord* block_start(const void* addr) const;
230   bool block_is_obj(const HeapWord* addr) const;
231 
232   jlong millis_since_last_gc();
233 
234   void prepare_for_verify();
235   PSHeapSummary create_ps_heap_summary();
236   virtual void print_on(outputStream* st) const;
237   virtual void print_on_error(outputStream* st) const;
238   virtual void print_gc_threads_on(outputStream* st) const;
239   virtual void gc_threads_do(ThreadClosure* tc) const;
240   virtual void print_tracing_info() const;
241 
242   void verify(VerifyOption option /* ignored */);
243 
244   // Resize the young generation.  The reserved space for the
245   // generation may be expanded in preparation for the resize.
246   void resize_young_gen(size_t eden_size, size_t survivor_size);
247 
248   // Resize the old generation.  The reserved space for the
249   // generation may be expanded in preparation for the resize.
250   void resize_old_gen(size_t desired_free_space);
251 
252   // Save the tops of the spaces in all generations
253   void record_gen_tops_before_GC() PRODUCT_RETURN;
254 
255   // Mangle the unused parts of all spaces in the heap
256   void gen_mangle_unused_area() PRODUCT_RETURN;
257 
258   // Call these in sequential code around the processing of strong roots.
259   class ParStrongRootsScope : public MarkScope {
260    public:
261     ParStrongRootsScope();
262     ~ParStrongRootsScope();
263   };
264 
265   GCMemoryManager* old_gc_manager() const { return _old_manager; }
266   GCMemoryManager* young_gc_manager() const { return _young_manager; }
267 };
268 
269 // Simple class for storing info about the heap at the start of GC, to be used
270 // after GC for comparison/printing.
271 class PreGCValues {
272 public:
273   PreGCValues(ParallelScavengeHeap* heap) :
274       _heap_used(heap->used()),
275       _young_gen_used(heap->young_gen()->used_in_bytes()),
276       _old_gen_used(heap->old_gen()->used_in_bytes()),
277       _metadata_used(MetaspaceUtils::used_bytes()) { };
278 
279   size_t heap_used() const      { return _heap_used; }
280   size_t young_gen_used() const { return _young_gen_used; }
281   size_t old_gen_used() const   { return _old_gen_used; }
282   size_t metadata_used() const  { return _metadata_used; }
283 
284 private:
285   size_t _heap_used;
286   size_t _young_gen_used;
287   size_t _old_gen_used;
288   size_t _metadata_used;
289 };
290 
291 // Class that can be used to print information about the
292 // adaptive size policy at intervals specified by
293 // AdaptiveSizePolicyOutputInterval.  Only print information
294 // if an adaptive size policy is in use.
295 class AdaptiveSizePolicyOutput : AllStatic {
296   static bool enabled() {
297     return UseParallelGC &&
298            UseAdaptiveSizePolicy &&
299            log_is_enabled(Debug, gc, ergo);
300   }
301  public:
302   static void print() {
303     if (enabled()) {
304       ParallelScavengeHeap::heap()->size_policy()->print();
305     }
306   }
307 
308   static void print(AdaptiveSizePolicy* size_policy, uint count) {
309     bool do_print =
310         enabled() &&
311         (AdaptiveSizePolicyOutputInterval > 0) &&
312         (count % AdaptiveSizePolicyOutputInterval) == 0;
313 
314     if (do_print) {
315       size_policy->print();
316     }
317   }
318 };
319 
320 #endif // SHARE_GC_PARALLEL_PARALLELSCAVENGEHEAP_HPP